find the minimum value for the mass m that would just begin to accelerate the 5.7 kg block up the hill.

Question

The ramp has an angle of 35 degrees above the horizontal. m₁ on the ramp is 5.7 kg; m₂ is connected to m₁ by a pulley and is suspended in the air next to the ramp. m₂ is the unknown. (Sorry I couldn't get a picture for it) what is the minimum value for the mass m₂ that would just begin to accelerate the 5.7 kg block up the hill?

ANSWERS: μ_s = 0.75, μ_k = 0.35, m₂ = 6.77 kg

how can I solve this problem? Thank you in advance.

Answer 1

1) Draw two FBD for m1 and m2

2) System to Remain in Equilibrium

mew*mgcos(theta) + mgsin(theta) = T = mg

factor out g

0.75*m*cos(35) + m*sin(35) = m

m = 6.76 kg

- minimum for acceleration